# Source code for sagenb.misc.support

    # -*- coding: utf-8 -*
    """
    Support for Notebook Introspection and Setup

    AUTHORS:

    - William Stein (much of this code is from IPython).

    - Nick Alexander
    """
    from six import iteritems, text_type

    import os
    import base64
    import string
    import sys

    from .misc import cython, session_init
    from . import sageinspect

    try:
        from sage.misc.sagedoc import format_src
    except ImportError:
        # Fallback
        def format_src(s, *args, **kwds):
            return s

    try:
        from sagenb.misc.sphinxify import sphinxify, is_sphinx_markup
    except ImportError as msg:
        print(msg)
        print("Sphinx docstrings not available.")
        # Don't do any Sphinxifying if sphinx's dependencies aren't around
        def sphinxify(s):
            return s
        def is_sphinx_markup(s):
            return False

    try:
        from sage.misc.displayhook import DisplayHook
        sys.displayhook = DisplayHook()
    except ImportError as msg:
        print(msg)
        print('Graphics will not be shown automatically')

    ######################################################################
    # Initialization
    ######################################################################
    EMBEDDED_MODE = False
    sage_globals = None
    globals_at_init = None
    global_names_at_init = None

    def init(object_directory=None, globs={}):
        r"""
        Initialize Sage for use with the web notebook interface.
        """
        global sage_globals, globals_at_init, global_names_at_init
        global EMBEDDED_MODE

        os.environ['PAGER'] = 'cat'

        sage_globals = globs
        #globals_at_init = set(globs.keys())
        globals_at_init = globs.values()
        global_names_at_init = set(globs.keys())
        EMBEDDED_MODE = True

        setup_systems(globs)
        session_init(globs)

        # Ugly cruft.  Initialize the embedded mode of the old Sage
        # notebook, which is going to be included in old copies of Sage
        # forever.
        try:
            import sage.server.support
            sage.server.support.EMBEDDED_MODE = True
        except ImportError:
            pass
        # Also initialize EMBEDDED_MODE in Sage's misc.sageinspect module,
        # which is used to format docstrings in the notebook.
        try:
            import sage.misc.sageinspect
            sage.misc.sageinspect.EMBEDDED_MODE = True
        except ImportError:
            pass

    def setup_systems(globs):
        from .misc import InlineFortran
        fortran = InlineFortran(globs)
        globs['fortran'] = fortran

    ######################################################################
    # Introspection
    ######################################################################
    def help(obj):
        """
        Display HTML help for ``obj``, a Python object, module, etc.  This
        help is often more extensive than that given by 'obj?'.  This
        function does not return a value --- it prints HTML as a side
        effect.

        .. note::

           This a wrapper around the built-in help. If formats the output
           as HTML without word wrap, which looks better in the notebook.

        INPUT:

        -  ``obj`` - a Python object, module, etc.

        TESTS::

            sage: import numpy.linalg
            sage: current_dir = os.getcwd()
            sage: os.chdir(tmp_dir('server_doctest'))
            sage: sagenb.misc.support.help(numpy.linalg.norm)
            <html><table notracebacks bgcolor="#386074" cellpadding=10 cellspacing=10><tr><td bgcolor="#f5f5f5"><font color="#37546d">
            &nbsp;&nbsp;&nbsp;<a target='_new' href='cell://docs-....html'>Click to open help window</a>&nbsp;&nbsp;&nbsp;
            <br></font></tr></td></table></html>
            sage: os.chdir(current_dir)
        """
        from pydoc import resolve, html, describe
        import sagenb.notebook.interact as interact

        print('<html><table notracebacks bgcolor="#386074" cellpadding=10 cellspacing=10><tr><td bgcolor="#f5f5f5"><font color="#37546d">')
        object, name = resolve(obj)
        page = html.page(describe(object), html.document(object, name))
        page = page.replace('<a href','<a ')
        n = 0
        while True:
            filename = 'docs-%s.html'%n
            if not os.path.exists(filename): break
            n += 1
        open(filename, 'w').write(page)
        print("&nbsp;&nbsp;&nbsp;<a target='_new' href='cell://%s'>Click to open help window</a>&nbsp;&nbsp;&nbsp;" % filename)
        print('<br></font></tr></td></table></html>')

    def get_rightmost_identifier(s):
        X = string.ascii_letters + string.digits + '._'
        i = len(s)-1
        while i >= 0 and s[i] in X:
            i -= 1
        return s[i+1:]

    def completions(s, globs, format=False, width=90, system="None"):
        """
        Return a list of completions in the given context.

        INPUT:

        - ``globs`` - a string:object dictionary; context in which to
          search for completions, e.g., :func:`globals()`

        - ``format`` - a bool (default: False); whether to tabulate the
          list

        - ``width`` - an int; character width of the table

        - ``system`` - a string (default: 'None'); system prefix for the
          completions

        OUTPUT:

        - a list of strings, if ``format`` is False, or a string
        """
        if system not in ['sage', 'python']:
            prepend = system + '.'
            s = prepend + s
        else:
            prepend = ''
        n = len(s)
        if n == 0:
            return '(empty string)'
        try:
            if not '.' in s and not '(' in s:
                v = [x for x in globs.keys() if x[:n] == s] + \
                    [x for x in __builtins__.keys() if x[:n] == s]
            else:
                if not ')' in s:
                    i = s.rfind('.')
                    method = s[i+1:]
                    obj = s[:i]
                    n = len(method)
                else:
                    obj = preparse(s)
                    method = ''
                try:
                    O = eval(obj, globs)
                    D = dir(O)
                    try:
                        D += O.trait_names()
                    except (AttributeError, TypeError):
                        pass
                    if method == '':
                        v = [obj + '.'+x for x in D if x and x[0] != '_']
                    else:
                        v = [obj + '.'+x for x in D if x[:n] == method]
                except Exception:
                    v = []
            v = list(set(v))   # make unique
            v.sort()
        except Exception:
            v = []

        if prepend:
            i = len(prepend)
            v = [x[i:] for x in v]

        if format:
            if len(v) == 0:
                return "No completions of '%s' currently defined"%s
            else:
                return tabulate(v, width)
        return v

    def docstring(obj_name, globs, system='sage'):
        r"""
        Format an object's docstring to process and display in the Sage
        notebook.

        INPUT:

        - ``obj_name`` - a string; a name of an object

        - ``globs`` - a string:object dictionary; a context in which to
          evaluate ``obj_name``

        - ``system`` - a string (default: 'sage'); the system to which to
          confine the search

        OUTPUT:

        - a string containing the object's file, type, definition, and
          docstring or a message stating the object is not defined

        AUTHORS:

        - William Stein: partly taken from IPython for use in Sage

        - Nick Alexander: extensions

        TESTS:

        Check that Trac 10860 is fixed and we can handle Unicode help
        strings in the notebook, see also Trac 26906::

            sage: from sagenb.misc.support import init, docstring
            sage: init()
            sage: D = docstring("r.lm", globs=globals())
        """
        if system not in ['sage', 'python']:
            obj_name = system + '.' + obj_name
        try:
            obj = eval(obj_name, globs)
        except (AttributeError, NameError, SyntaxError):
            return "No object '%s' currently defined."%obj_name
        s  = ''
        newline = "\n\n"  # blank line to start new paragraph
        try:
            filename = sageinspect.sage_getfile(obj)
            #i = filename.find('site-packages/sage/')
            #if i == -1:
            s += '**File:** %s'%filename
            s += newline
            #else:
            #    file = filename[i+len('site-packages/sage/'):]
            #    s += 'File:        <html><a href="src_browser?%s">%s</a></html>\n'%(file,file)
        except TypeError:
            pass
        s += '**Type:** %s'%type(obj)
        s += newline
        s += '**Definition:** %s' % sageinspect.sage_getdef(obj, obj_name)
        s += newline
        s += '**Docstring:**'
        s += newline
        s += sageinspect.sage_getdoc(obj, obj_name)
        s = s.rstrip()
        return html_markup(s.decode('utf-8'))

    def html_markup(s):
        try:
            from sagenb.misc.sphinxify import sphinxify, is_sphinx_markup
        except ImportError:
            # sphinx not available
            def is_sphinx_markup(s): return False

        if is_sphinx_markup(s):
            try:
                return sphinxify(s)
            except:
                pass
        # Not in ReST format, so use docutils
        # to process the preamble ("**File:**" etc.)  and put
        # everything else in a <pre> block.
        i = s.find("**Docstring:**")
        if i != -1:
            preamble = s[:i+14]
            from docutils.core import publish_parts
            preamble = publish_parts(s[:i+14], writer_name='html')['body']
            s = s[i+14:]
        else:
            preamble = ""
        return '<div class="docstring">' + preamble + '<pre>' + s + '</pre></div>'

    def source_code(s, globs, system='sage'):
        r"""
        Format an object's source code to process and display in the
        Sage notebook.

        INPUT:

        - ``s`` - a string; a name of an object

        - ``globs`` - a string:object dictionary; a context in which to
          evaluate ``s``

        - ``system`` - a string (default: 'sage'); the system to which to
          confine the search

        OUTPUT:

        - a string containing the object's file, starting line number, and
          source code

        AUTHORS:

        - William Stein: partly taken from IPython for use in Sage

        - Nick Alexander: extensions
        """
        if system not in ['sage', 'python']:
            s = system + '.' + s

        try:
            obj = eval(s, globs)
        except NameError:
            return html_markup("No object %s"%s)

        try:
            try:
                return html_markup(obj._sage_src_())
            except:
                pass
            newline = "\n\n"  # blank line to start new paragraph
            indent = "    "   # indent source code to mark it as a code block

            filename = sageinspect.sage_getfile(obj)
            try:
                lines, lineno = sageinspect.sage_getsourcelines(obj)
            except IOError as msg:
                return html_markup(str(msg))
            src = indent.join(lines)
            src = indent + format_src(src)
            if not lineno is None:
                output = "**File:** %s"%filename
                output += newline
                output += "**Source Code** (starting at line %s)::"%lineno
                output += newline
                output += src
            return html_markup(output)

        except (TypeError, IndexError):
            return html_markup("Source code for {} is not available.".format(s) +
                               "\nUse {}? to see the documentation.".format(s))

    def tabulate(v, width=90, ncols=3):
        e = len(v)
        if e == 0:
            return ''
        while True:
            col_widths = []
            nrows = e//ncols + 1
            for c in range(ncols):
                m = max([0] + [len(v[r+c*nrows]) for r in range(nrows) if r+c*nrows < e])
                col_widths.append(m+3)
            if ncols > 1 and max(col_widths + [0]) > width//ncols:
                ncols -= 1
            else:
                break
        s = ''
        for r in range(nrows):
            for c in range(ncols):
                i = r + c * nrows
                if i < e:
                    w = v[i]
                    s += w + ' '*(col_widths[c] - len(w))
            s += '\n'
        return s

    def syseval(system, cmd, dir=None):
        """
        Evaluate an input with a "system" object that can evaluate inputs
        (e.g., python, gap).

        INPUT:

        - ``system`` - an object with an eval method that takes an input

        - ``cmd`` - a string input

        - ``sage_globals`` - a string:object dictionary

        - dir - a string (default: None); an optional directory to change
          to before calling :func:`system.eval`

        OUTPUT:

        - :func:`system.eval`'s output

        EXAMPLES::

            sage: from sage.misc.python import python
            sage: sagenb.misc.support.syseval(python, '2+4//3')
            3
            ''
            sage: sagenb.misc.support.syseval(python, 'import os; os.chdir(".")')
            ''
            sage: sagenb.misc.support.syseval(python, 'import os; os.chdir(1,2,3)')
            Traceback (most recent call last):
            ...
            TypeError: chdir() takes exactly 1 argument (3 given)
            sage: sagenb.misc.support.syseval(gap, "2+3")
            '5'
        """
        if dir:
            if hasattr(system.__class__, 'chdir'):
                system.chdir(dir)
        if isinstance(cmd, text_type):
            cmd = cmd.encode('utf-8', 'ignore')
        return system.eval(cmd, sage_globals, locals=sage_globals)

    ######################################################################
    # Cython
    ######################################################################
    def cython_import(filename, verbose=False, compile_message=False,
                     use_cache=False, create_local_c_file=True):
        """
        Compile a file containing Cython code, then import and return the
        module.  Raises an ``ImportError`` if anything goes wrong.

        INPUT:

        - ``filename`` - a string; name of a file that contains Cython
          code

        OUTPUT:

        - the module that contains the compiled Cython code.
        """
        name, build_dir = cython(filename, verbose=verbose,
                                 compile_message=compile_message,
                                                use_cache=use_cache,
                                                create_local_c_file=create_local_c_file)
        sys.path.append(build_dir)
        return __import__(name)

    def cython_import_all(filename, globals, verbose=False, compile_message=False,
                         use_cache=False, create_local_c_file=True):
        """
        Imports all non-private (i.e., not beginning with an underscore)
        attributes of the specified Cython module into the given context.
        This is similar to::

            from module import *

        Raises an ``ImportError`` exception if anything goes wrong.

        INPUT:

        - ``filename`` - a string; name of a file that contains Cython
          code
        """
        m = cython_import(filename, verbose=verbose, compile_message=compile_message,
                         use_cache=use_cache,
                         create_local_c_file=create_local_c_file)
        for k, x in iteritems(m.__dict__):
            if k[0] != '_':
                globals[k] = x

    ###################################################
    # Preparser
    ###################################################
    try:
        from sage.repl.preparse import preparse, preparse_file
        def do_preparse():
            """
            Return True if the preparser is set to on, and False otherwise.
            """
            import sage.repl.interpreter
            return sage.repl.interpreter._do_preparse
    except ImportError:
        def preparse(line, *args, **kwds):
            return line
        def preparse_file(contents, *args, **kwds):
            return contents
        def do_preparse():
            """
            Return True if the preparser is set to on, and False otherwise.
            """
            return False

    ########################################################################
    #
    # Automatic Creation of Variable Names
    #
    # See the docstring for automatic_names below for an explanation of how
    # this works.
    #
    ########################################################################

    _automatic_names = False
    # We wrap everything in a try/catch, in case this is being imported
    # without the sage library present, e.g., in FEMhub.
    try:
        from sage.symbolic.all import Expression, SR
        class AutomaticVariable(Expression):
            """
            An automatically created symbolic variable with an additional
            :meth:`__call__` method designed so that doing self(foo,...)
            results in foo.self(...).
            """
            def __call__(self, *args, **kwds):
                """
                Call method such that self(foo, ...) is transformed into
                foo.self(...).  Note that self(foo=...,...) is not
                transformed, it is treated as a normal symbolic
                substitution.
                """
                if len(args) == 0:
                    return Expression.__call__(self, **kwds)
                return args[0].__getattribute__(str(self))(*args[1:], **kwds)

        def automatic_name_eval(s, globals, max_names=10000):
            r"""
            Exec the string ``s`` in the scope of the ``globals``
            dictionary, and if any :exc:`NameError`\ s are raised, try to
            fix them by defining the variable that caused the error to be
            raised, then eval again.  Try up to ``max_names`` times.

            INPUT:

            - ``s`` -- a string
            - ``globals`` -- a dictionary
            - ``max_names`` -- a positive integer (default: 10000)
            """
            # This entire automatic naming system really boils down to
            # this bit of code below.  We simply try to exec the string s
            # in the globals namespace, defining undefined variables and
            # functions until everything is defined.
            for _ in range(max_names):
                try:
                    exec(s , globals)
                    return
                except NameError as msg:
                    # Determine if we hit a NameError that is probably
                    # caused by a variable or function not being defined:
                    if len(msg.args) == 0: raise  # not NameError with
                                                  # specific variable name
                    v = msg.args[0].split("'")
                    if len(v) < 2: raise  # also not NameError with
                                          # specific variable name We did
                                          # find an undefined variable: we
                                          # simply define it and try
                                          # again.
                    nm = v[1]
                    globals[nm] = AutomaticVariable(SR, SR.var(nm))
            raise NameError("Too many automatic variable names and functions created (limit=%s)" % max_names)

        def automatic_name_filter(s):
            """
            Wrap the string ``s`` in a call that will cause evaluation of
            ``s`` to automatically create undefined variable names.

            INPUT:

               - ``s`` -- a string

            OUTPUT:

               - a string
            """
            return '_support_.automatic_name_eval(_support_.base64.b64decode("%s"),globals())'%base64.b64encode(s)

        def automatic_names(state=None):
            """
            Turn automatic creation of variables and functional calling of
            methods on or off.  Returns the current ``state`` if no
            argument is given.

            This ONLY works in the Sage notebook.  It is not supported on
            the command line.

            INPUT:

            - ``state`` -- a boolean (default: None); whether to turn
              automatic variable creation and functional calling on or off

            OUTPUT:

            - a boolean, if ``state`` is None; otherwise, None

            EXAMPLES::

                sage: automatic_names(True)      # not tested
                sage: x + y + z                  # not tested
                x + y + z

            Here, ``trig_expand``, ``y``, and ``theta`` are all
            automatically created::

                sage: trig_expand((2*x + 4*y + sin(2*theta))^2)   # not tested
                4*(sin(theta)*cos(theta) + x + 2*y)^2

            IMPLEMENTATION: Here's how this works, internally.  We define
            an :class:`AutomaticVariable` class derived from
            :class:`~sage.symbolic.all.Expression`.  An instance of
            :class:`AutomaticVariable` is a specific symbolic variable,
            but with a special :meth:`~AutomaticVariable.__call__` method.
            We overload the call method so that ``foo(bar, ...)`` gets
            transformed to ``bar.foo(...)``.  At the same time, we still
            want expressions like ``f^2 - b`` to work, i.e., we don't want
            to have to figure out whether a name appearing in a
            :exc:`NameError` is meant to be a symbolic variable or a
            function name. Instead, we just make an object that is both!

            This entire approach is very simple---we do absolutely no
            parsing of the actual input.  The actual real work amounts to
            only a few lines of code.  The primary catch to this approach
            is that if you evaluate a big block of code in the notebook,
            and the first few lines take a long time, and the next few
            lines define 10 new variables, the slow first few lines will
            be evaluated 10 times.  Of course, the advantage of this
            approach is that even very subtle code that might inject
            surprisingly named variables into the namespace will just work
            correctly, which would be impossible to guarantee with static
            parsing, no matter how sophisticated it is.  Finally, given
            the target audience: people wanting to simplify use of Sage
            for Calculus for undergrads, I think this is an acceptable
            tradeoff, especially given that this implementation is so
            simple.
            """
            global _automatic_names
            if state is None:
                return _automatic_names
            _automatic_names = bool(state)

    except ImportError:
        pass

    from sagenb.misc.format import displayhook_hack

    def preparse_worksheet_cell(s, globals):
        """
        Preparse the contents of a worksheet cell in the notebook,
        respecting the user using ``preparser(False)`` to turn off the
        preparser.  This function calls
        :func:`~sage.repl.preparse.preparse_file` which also reloads
        attached files.  It also does displayhook formatting by calling
        the :func:`~sagenb.notebook.interfaces.format.displayhook_hack`
        function.

        INPUT:

        - ``s`` - a string containing code

        - ``globals`` - a string:object dictionary; passed directly to
          :func:`~sage.repl.preparse.preparse_file`

        OUTPUT:

            - a string
        """
        if do_preparse():
            s = preparse_file(s, globals=globals)
        s = displayhook_hack(s)
        if _automatic_names:
            s = automatic_name_filter(s)
        return s